EP300 facilitates human trophoblast stem cell differentiation

Early placenta development involves cytotrophoblast differentiation into extravillous trophoblast (EVT) and syncytiotrophoblast (STB). Defective trophoblast development and function may result in severe pregnancy complications, including fetal growth restriction and pre-eclampsia. The incidence of these complications is increased in pregnancies of fetuses affected by Rubinstein-Taybi syndrome, a developmental disorder predominantly caused by heterozygous mutations in CREB-binding protein (CREBBP) or E1A-binding protein p300 (EP300). Although the acetyltransferases CREBBP and EP300 are paralogs with many overlapping functions, the increased incidence of pregnancy complications is specific for EP300 mutations. We hypothesized that these complications have their origin in early placentation and that EP300 is involved in that process. Therefore, we investigated the role of EP300 and CREBBP in trophoblast differentiation, using human trophoblast stem cells (TSCs) and trophoblast organoids. We found that pharmacological CREBBP/EP300 inhibition blocks differentiation of TSCs into both EVT and STB lineages, and results in an expansion of TSC-like cells under differentiation-inducing conditions. Specific targeting by RNA interference or CRISPR/Cas9-mediated mutagenesis demonstrated that knockdown of EP300 but not CREBBP, inhibits trophoblast differentiation, consistent with the complications seen in Rubinstein-Taybi syndrome pregnancies. By transcriptome sequencing, we identified transforming growth factor alpha (TGFA, encoding TGF-α) as being strongly upregulated upon EP300 knockdown. Moreover, supplementing differentiation medium with TGF-α, which is a ligand for the epidermal growth factor receptor (EGFR), likewise affected trophoblast differentiation and resulted in increased TSC-like cell proliferation. These findings suggest that EP300 facilitates trophoblast differentiation by interfering with at least EGFR signaling, pointing towards a crucial role for EP300 in early human placentation.

CBP and p300 Jointly Maintain Neural Progenitor Viability but Play Unique Roles in the Differentiation of Neural Lineages

The paralogous lysine acetyltransferases 3 (KAT3), CBP and P300, play critical roles during neurodevelopment, but their specific roles in neural precursors maintenance and differentiation remain obscure. In fact, it is still unclear whether these proteins are individually or jointly essential in processes such as proliferation of neural precursors, differentiation to specific neural cell types, or both. Here, we use subventricular zone-derived neurospheres as a potential ex vivo developmental model to analyze the proliferation and differentiation of neural stem cells (NSCs) lacking CBP, p300, or both proteins. The results showed that CBP and p300 are not individually essential for maintenance and proliferation of NSCs, although their combined ablation seriously compromised cell division. In turn, the absence of either of the two proteins compromised the differentiation of NSC into the neuronal and astrocytic lineages. Single-nucleus RNA sequencing analysis of neural cell cultures derived from CBP or p300 mutant neurospheres revealed divergent trajectories of neural differentiation upon CBP or p300 ablation, confirming unique functions and nonredundant roles in neural development. These findings contribute to a better understanding of the shared and individual roles of KAT3 proteins in neural differentiation and the etiology of neurodevelopmental disorders caused by their deficiency.

The development of early social cognitive skills in neurogenetic syndromes associated with autism: Cornelia de Lange, fragile X and Rubinstein-Taybi syndromes

BACKGROUND

Cornelia de Lange (CdLS), Fragile X (FXS) and Rubinstein-Taybi syndromes (RTS) evidence unique profiles of autistic characteristics. To delineate these profiles further, the development of early social cognitive abilities in children with CdLS, FXS and RTS was compared to that observed in typically developing (TD) and autistic (AUT) children.

METHODS

Children with CdLS (N = 22), FXS (N = 19) and RTS (N = 18), completed the Early Social Cognition Scale (ESCogS). Extant data from AUT (N = 19) and TD (N = 86) children were used for comparison.

RESULTS

Similar to AUT children, children with CdLS, FXS and RTS showed an overall delay in passing ESCogS tasks. Children with CdLS showed a similar degree of delay to AUT children and greater delay than children with FXS and RTS. The CdLS, FXS and RTS groups did not pass tasks in the same sequence observed in TD and AUT children. Children with CdLS (p = 0.04), FXS (p = 0.02) and RTS (p = 0.04) performed better on tasks requiring understanding simple intentions in others significantly more than tasks requiring joint attention skills.

CONCLUSIONS

An underlying mechanism other than general cognitive delay may be disrupting early social cognitive development in children with CdLS, FXS and RTS. Factors that may disrupt early social cognitive development within these syndromes are discussed.

Insights into the Role of the Microbiota and of Short-Chain Fatty Acids in Rubinstein-Taybi Syndrome

The short-chain fatty acid butyrate, produced by the gut microbiota, acts as a potent histone deacetylase (HDAC) inhibitor. We assessed possible ameliorative effects of butyrate, relative to other HDAC inhibitors, in in vitro and in vivo models of Rubinstein–Taybi syndrome (RSTS), a severe neurodevelopmental disorder caused by variants in the genes encoding the histone acetyltransferases CBP and p300. In RSTS cell lines, butyrate led to the patient-specific rescue of acetylation defects at subtoxic concentrations. Remarkably, we observed that the commensal gut microbiota composition in a cohort of RSTS patients is significantly depleted in butyrate-producing bacteria compared to healthy siblings. We demonstrate that the effects of butyrate and the differences in microbiota composition are conserved in a Drosophila melanogaster mutant for CBP, enabling future dissection of the gut–host interactions in an in vivo RSTS model. This study sheds light on microbiota composition in a chromatinopathy, paving the way for novel therapeutic interventions.

A Novel CREBBP in-Frame Deletion Variant in a Chinese Girl with Atypical Rubinstein-Taybi Syndrome Phenotypes

Loss-of-function variants in CREBBP or EP300 result in Rubinstein-Taybi syndrome (RSTS). The previously reported cluster of variants in the last part of exon 30 and the beginning of exon 31 of CREBBP, overlapping with the ZNF2 (zinc finger, ZZ-type; residues 1701 to 1744) and ZNF3 (zinc finger, TAZ-type; residues 1764 to 1853) domains, is associated with atypical RSTS. The main features include developmental delay, short stature, microcephaly, distinctive facial features, autistic behavior, feeding difficulties, recurrent upper airway infections, and hearing impairment. Here, we report a 2-year-7-month-old Chinese girl presenting mild cognitive impairments, developmental delay, short stature, recurrent upper airway infections, and facial dysmorphism that resembled the phenotypes of previously reported atypical RSTS patients. The characteristic facial and limb dysmorphism for RSTS was absent in our patient. In addition, our patient exhibited novel phenotypes including attention deficit hyperactivity disorder (ADHD), sleep problem, and abnormal walking posture. Whole-exome sequencing (WES) identified a novel de novo in-frame deletion variant in the beginning of exon 30 of CREBBP (NM_004380:c.4897_4899delTTC, p.Phe1633del) in the HAT domain where no pathogenic variants have been previously reported to be responsible for atypical RSTS. Our case allows us to more accurately define the borders of the CREBBP coding sequence resulting in atypical RSTS, which are extended to the beginning of exon 30 (residue 1633) at the 5' end of CREBBP in the HAT domain, and reveals novel phenotypes observed in our atypical Chinese RSTS patient.

Prevalence of Immunological Defects in a Cohort of 97 Rubinstein-Taybi Syndrome Patients

Although recurrent infections in Rubinstein-Taybi syndrome (RSTS) are common, and probably multifactorial, immunological abnormalities have not been extensively described with only isolated cases or small case series of immune deficiency and dysregulation having been reported. The objective of this study was to investigate primary immunodeficiency (PID) and immune dysregulation in an international cohort of patients with RSTS. All published cases of RSTS were identified. The corresponding authors and researchers involved in the diagnosis of inborn errors of immunity or genetic syndromes were contacted to obtain up-to-date clinical and immunological information. Ninety-seven RSTS patients were identified. For 45 patients, we retrieved data from the published reports while for 52 patients, a clinical update was provided. Recurrent or severe infections, autoimmune/autoinflammatory complications, and lymphoproliferation were observed in 72.1%, 12.3%, and 8.2% of patients. Syndromic immunodeficiency was diagnosed in 46.4% of individuals. Despite the broad heterogeneity of immunodeficiency disorders, antibody defects were observed in 11.3% of subjects. In particular, these patients presented hypogammaglobulinemia associated with low B cell counts and reduction of switched memory B cell numbers. Immunoglobulin replacement therapy, antibiotic prophylaxis, and immunosuppressive treatment were employed in 16.4%, 8.2%, and 9.8% of patients, respectively. Manifestations of immune dysfunctions, affecting mostly B cells, are more common than previously recognized in patients with RSTS. Full immunological assessment is warranted in these patients, who may require detailed investigation and specific supportive treatment. Graphical Abstract.

Ultrasound 2-D and 3-D diagnosis of Rubinstein-Taybi syndrome in a 21-week-old fetus

Rubinstein-Taybi syndrome is a rare genetic multisystem disorder with an estimated prevalence between 1 per 100,000-125,000 live births. Diagnosis is usually clinical and subsequent to birth. In fact, the rarity of the syndrome and the presence of aspecific morphologic anomalies make prenatal diagnosis challenging. The aim of our work is to analyze ultrasonographic findings, detectable with a combination of 2D and 3D techniques, which may increase the sensitivity of in utero diagnosis of this condition. We report a case of a sonographic prenatal diagnosis of broad and angulated thumbs and halluces and of an abnormal ductus venosus at 21 weeks of gestational age. These findings allowed us to suspect Rubinstein-Taybi syndrome. An accurate ultrasonographic examination may allow a prenatal diagnosis of those syndromes which are usually diagnosed after birth.

A case with Rubinstein-Taybi syndrome: A novel frameshift mutation in the CREBBP gene

Rubinstein-Taybi syndrome (RSTS) is a developmental disorder characterized by a wide spectrum of multiple congenital anomalies and cognitive impairment. RSTS is primarily due to mutations in CREBBP (approximately 55% of cases) or EP300 (approximately 8% of cases) genes. A 2 month-old boy had atypical facial findings such as low anterior hairline, triangular face, hirsutism on forehead, down-slanting palpebral fissures, beaked nose, broad nasal bridge, triangular mouth and pointed chin and skeletal finding including broad great thumbs and halluces, and accessory nipple. With this paper, we reported a novel frameshift mutation which is led to premature stop codon in CREBBP gene. As a result, c.2057dupC, reported in this paper enlarges the molecular spectrum of disease-causing CREBBP gene.

Lacrimal drainage anomalies in Rubinstein-Taybi syndrome: case report and review of literature

Rubinstein-Taybi syndrome is a rare multisystem disorder characterized by broad thumbs and first toes, short stature, microcephaly, delayed milestones, beak nose, and hypertelorism. Lacrimal drainage anomalies are not uncommon in this syndrome. We present a patient with Rubinstein-Taybi syndrome with bilateral congenital nasolacrimal duct obstruction and left-sided grossly dilated nasolacrimal duct.

Diverse Profiles of Anxiety Related Disorders in Fragile X, Cornelia de Lange and Rubinstein-Taybi Syndromes

Anxiety disorders are heightened in specific genetic syndromes in comparison to intellectual disability of heterogeneous aetiology. In this study, we described and contrasted anxiety symptomatology in fragile X (FXS), Cornelia de Lange (CdLS) and Rubinstein-Taybi syndromes (RTS), and compared the symptomatology to normative data for typically-developing children and children diagnosed with an anxiety disorder. Scores did not differ between children diagnosed with an anxiety disorder and (a) participants with FXS on social phobia, panic/agoraphobia, physical injury fears, and obsessive-compulsive subscales (b) participants with CdLS on separation anxiety, generalized anxiety, panic/agoraphobia, physical injury fears and obsessive-compulsive subscales, and (c) participants with RTS on panic/agoraphobia and obsessive-compulsive subscales. The results highlight divergent profiles of anxiety symptomatology between these groups.

Primary Diffuse Large B-Cell Lymphoma in a Patient with Rubinstein-Taybi Syndrome: Case Report and Review of the Literature

BACKGROUND

Rubinstein-Taybi syndrome (RSTS) is a rare, congenital syndrome that is known to be associated with neoplasms of various organ systems. Evaluation and treatment of such patients is challenging, given the cognitive delay and heterogeneity of pathologic presentations that define this syndrome.

CASE DESCRIPTION

Presented here is a case of a patient with RSTS, diagnosed at birth, who presented with subtle symptoms of lethargy and a change in behavior. He was found to have a large (7.0-cm × 4.7-cm), right-sided brain mass that was eventually diagnosed as a primary central nervous system lymphoma.

CONCLUSIONS

To the best of our knowledge, this is the first reported case of a primary central nervous system lymphoma presenting in a patient with RSTS. This was confirmed through microscopic and histologic studies. The large size attained by this mass in our patient highlights the increased scrutiny and surveillance needed to provide the best care for these patients. A multidisciplinary team approach is ideal as successful treatment of our patient using surgical debulking, appropriate chemotherapy, and close postoperative follow-up has resulted in an excellent clinical outcome.

Dissociation of Cross-Sectional Trajectories for Verbal and Visuo-Spatial Working Memory Development in Rubinstein-Taybi Syndrome

Working memory (WM) impairments might amplify behavioural difference in genetic syndromes. Murine models of Rubinstein–Taybi syndrome (RTS) evidence memory impairments but there is limited research on memory in RTS. Individuals with RTS and typically developing children completed WM tasks, with participants with RTS completing an IQ assessment and parents/carers completing the Vineland Adaptive Behavior Scales. A cross-sectional trajectory analysis was conducted. There were significant WM span deficits in RTS relative to mental age. Verbal WM span was positively associated with mental age; however, this was not observed for visuo-spatial span. There is a dissociation between WM domains in RTS. Individuals may have difficulties with tasks relying on WM span, above difficulties predicted by overall ability.

The Social Security Administration's Compassionate Allowances Initiative: Condition Spotlight on Rubinstein-Taybi Syndrome

The Social Security Administration (SSA) Compassionate Allowances List (CAL) was created in 2008, generating a mechanism within SSA for identifying diseases and other medical conditions that by definition meet social security's standards for disability benefits. Currently, over 200 conditions are included in this expedited review program, though few of them are neurodevelopmental in nature. Exploration of a novel method for inclusion of additional conditions on CAL was undertaken using one condition as an exemplar. Peer-reviewed literature available in academic databases was reviewed and used as empirical evidence to demonstrate whether Rubinstein-Taybi syndrome (RTS) invariably met the three disability criteria set forth by SSA. After in-depth exploration of the empirical literature, RTS was found to meet SSA's definition, suggesting this condition should receive consideration as an addition to the Compassionate Allowances Initiative.

Whole exome sequencing reveals EP300 mutation in mildly affected female: expansion of the spectrum

Rubinstein–Taybi syndrome is associated with intellectual and physical features. CREBBP and EP300 are causative. Few cases of EP300 mutations are reported. We report a case with mild features of RSTS and EP300 mutation on exome sequencing. This illustrates the utility of exome sequencing to expand every genetic phenotype.

Anesthetic management for thoracic surgery in Rubinstein-Taybi syndrome

Rubinstein-Taybi syndrome (RTS) is a chromosomopathy associated to molecular mutations or microdeletions of chromosome 16. It has an incidence of 1:125,000-700,000 live births. RTS patients present craniofacial and thoracic anomalies that lead to a probable difficult-to-manage airway and ventilation. They also present mental retardation and comorbidity, such as congenital cardiac defects, pulmonary structural anomalies and recurrent respiratory infections, which increase the risk of aspiration pneumonia. Cardiac arrhythmias have been reported after the use of certain drugs such as succinylcholine and atropine, in a higher incidence than in general population. There is an increased risk of postoperative apnea-hypopnea in these patients. We report the anesthetic management in a RTS patient undergoing emergent thoracic surgery due to oesophageal perforation and mediastinitis. Lung isolation was achieved with a bronchial blocker guided with a fiberoptic bronchoscope and one-lung ventilation was performed successfully.

Ultra-Rare Syndromes: The Example of Rubinstein-Taybi Syndrome

Rubinstein-Taybi syndrome (RSTS) is a rare, congenital, plurimalformative, and neurodevelopmental disorder. Clinical diagnosis can be complicated by the heterogeneous clinical presentation and the lack of a consensus list of diagnostic criteria, and it is confirmed by molecular tests in approximately 55 to 78% of cases. The etiology is partially known with mutations in two functionally related genes: CREBBP and EP300. Notwithstanding the knowledge on clinical, genetic, and allelic heterogeneity, no clear genotype-phenotype correlation has yet been established. Standardized guidelines for the management of pediatric patients are available and therapy for RSTS patients is currently only symptomatic. In this article, several clinic and genetic aspects of RSTS are critically reviewed.

Epigenetic factors in intellectual disability: the Rubinstein-Taybi syndrome as a paradigm of neurodevelopmental disorder with epigenetic origin

The number of genetic syndromes associated with intellectual disability that are caused by mutations in genes encoding chromatin-modifying enzymes has sharply risen in the last decade. We discuss here a neurodevelopmental disorder, the Rubinstein-Taybi syndrome (RSTS), originated by mutations in the genes encoding the lysine acetyltransferases CBP and p300. We first describe clinical and genetic aspects of the syndrome to later focus on the insight provided by the research in animal models of this disease. These studies have not only clarified the molecular etiology of RSTS and helped to dissect the developmental and adult components of the syndrome but also contributed to outline some important connections between epigenetics and cognition. We finally discuss how this body of research has opened new venues for the therapeutic intervention of this currently untreatable disease and present some of the outstanding questions in the field. We believe that the progress in the understanding of this rare disorder also has important implications for other intellectual disability disorders that share an epigenetic origin.

Rubinstein-Taybi syndrome with agenesis of corpus callosum

Rubinstein-Taybi syndrome (RSTS) is a rare genetic disorder with characteristic morphological anomaly. Our patient was a 4.5-year-old girl came with features like broad thumbs, downward slanting palpebral fissures and mental retardation. Systemic abnormalities such as repeated infection, seizure with developmental delay were also associated with it. She was having head banging behavior abnormal slurring speech, incoordination while transferring things from one hand to other. Galaxy of clinical pictures and magnetic resonance imaging report helped to clinch the diagnosis as a case of "RSTS with corpus callosal agenesis" which to the best of our knowledge has never been reported in past from India.

Keloids: an unwanted spontaneity in rubinstein-taybi syndrome

Rubinstein-Taybi syndrome (RTS) is a rare developmental disorder comprising of mental retardation, unusual facial appearance, broad thumbs, and big toes. It is frequently associated with molecular lesions in the cAMP response element binding protein. Many cutaneous abnormalities are associated with RTS. Multiple spontaneous keloids are some of them. We hereby report a case of this rare syndrome associated with keloids without any preceding trauma.

Correction of thumb angulations after physiolysis of delta phalanges in a child with Rubinstein-Taybi syndrome: a case report

Resection of the midzone of the continuous epiphysis of a delta phalanx (physiolysis) and its replacement by a free-fat graft from local tissue was performed to improve severe radial angulation of the both thumbs in a 22-month-old child with Rubinstein–Taybi syndrome. Fifty-two months after surgery, satisfactory results were obtained for pinch function, appearance, and radiographic findings. Previous reports have indicated that corrective osteotomy of the thumbs in Rubinstein–Taybi syndrome has an associated risk of incomplete correction and >30% of recurrence, because severe preoperative deformities of the delta phalanx make angulatory osteotomies difficult. Additionally, physiolysis is a less invasive procedure than corrective osteotomy and offers a reduced risk of incomplete or excess correction, physeal injury, or osteonecrosis in younger children. Therefore, physiolysis appears to be useful as an initial means of correcting severe thumb angulations secondary to a delta phalanx. We reported a case in which the physiolysis of the delta phalanx significantly improved severe angular deformities of the thumbs in association with Rubinstein–Taybi syndrome.

Simulations suggest pharmacological methods for rescuing long-term potentiation

Congenital cognitive dysfunctions are frequently due to deficits in molecular pathways that underlie the induction or maintenance of synaptic plasticity. For example, Rubinstein-Taybi syndrome (RTS) is due to a mutation in cbp, encoding the histone acetyltransferase CREB-binding protein (CBP). CBP is a transcriptional co-activator for CREB, and induction of CREB-dependent transcription plays a key role in long-term memory (LTM). In animal models of RTS, mutations of cbp impair LTM and late-phase long-term potentiation (LTP). As a step toward exploring plausible intervention strategies to rescue the deficits in LTP, we extended our previous model of LTP induction to describe histone acetylation and simulated LTP impairment due to cbp mutation. Plausible drug effects were simulated by model parameter changes, and many increased LTP. However no parameter variation consistent with a effect of a known drug class fully restored LTP. Thus we examined paired parameter variations consistent with effects of known drugs. A pair that simulated the effects of a phosphodiesterase inhibitor (slowing cAMP degradation) concurrent with a deacetylase inhibitor (prolonging histone acetylation) restored normal LTP. Importantly these paired parameter changes did not alter basal synaptic weight. A pair that simulated the effects of a phosphodiesterase inhibitor and an acetyltransferase activator was similarly effective. For both pairs strong additive synergism was present. The effect of the combination was greater than the summed effect of the separate parameter changes. These results suggest that promoting histone acetylation while simultaneously slowing the degradation of cAMP may constitute a promising strategy for restoring deficits in LTP that may be associated with learning deficits in RTS. More generally these results illustrate how the strategy of combining modeling and empirical studies may provide insights into the design of effective therapies for improving long-term synaptic plasticity and learning associated with cognitive disorders.

Acute prenatal exposure to a moderate dose of valproic acid increases social behavior and alters gene expression in rats

Prenatal exposure to moderate doses of valproic acid (VPA) produces brainstem abnormalities, while higher doses of this teratogen elicit social deficits in the rat. In this pilot study, we examined effects of prenatal exposure to a moderate dose of VPA on behavior and on transcriptomic expression in three brain regions that mediate social behavior. Pregnant Long Evans rats were injected with 350 mg/kg VPA or saline on gestational day 13. A modified social interaction test was used to assess social behavior and social preference/avoidance during early and late adolescence and in adulthood. VPA-exposed animals demonstrated more social investigation and play fighting than control animals. Social investigation, play fighting, and contact behavior also differed as a function of age; the frequency of these behaviors increased in late adolescence. Social preference and locomotor activity under social circumstances were unaffected by treatment or age. Thus, a moderate prenatal dose of VPA produces behavioral alterations that are substantially different from the outcomes that occur following exposure to a higher dose. At adulthood, VPA-exposed subjects exhibited transcriptomic abnormalities in three brain regions: anterior amygdala, cerebellar vermis, and orbitofrontal cortex. A common feature among the proteins encoded by the dysregulated genes was their ability to be modulated by acetylation. Analysis of the expression of individual exons also revealed that genes involved in post-translational modification and epigenetic regulation had particular isoforms that were ubiquitously dysregulated across brain regions. The vulnerability of these genes to the epigenetic effects of VPA may highlight potential mechanisms by which prenatal VPA exposure alters the development of social behavior.

Rubinstein-taybi syndrome with psychosis

Rubinstein-Taybi syndrome (RTS) is a rare genetic disorder with characteristic physical anomalies. It is characterized by mental retardation, postnatal growth deficiency, microcephaly, specific facial characteristics, broad thumbs, and big toes. Behavioral problems are common with RTS; they include mental retardation, impulsivity, distractibility, instability of mood, stereotypes, poor coordination, atypical depression, and mania. To date, there is lack of literature on the presence of schizophrenia or non-affective psychosis with RTS. Here, we describe two cases where there is co-morbid psychosis with RTS. One case is diagnosed as paranoid schizophrenia and the other as psychosis possibly schizophrenia. Genetic analysis was not done due to unavailability. The possible etiological factors for the association of psychosis with RTS are discussed. Factors such as regulators of RNA polymerase II and hypoxia-inducible factor 1 alpha (HIF1A) may be some common etiological factors for the association of schizophrenia or non-affective psychosis and RTS. Schizophrenia / non-affective psychosis can be a comorbid psychiatric condition with RTS.